低速风洞引射短舱动力模拟技术新进展

引射短舱可以模拟发动机短舱的喷流影响，并部分模拟进气影响，能用于研究发动机短舱与机翼及增升装置的气动干扰特性，且具有研制周期短、造价低等特点，是在风洞中开展飞机/发动机一体化设计研究的一种重要试验技术。本文介绍了气动中心低速所在引射短舱设计技术和试验技术方面的新进展。采用商业软件对引射短舱进行了三维流场数值模拟，获得了引射短舱性能和三维流场信息。对引射短舱内部流场进行了分析和研究，对引射喷嘴数量、位置进行了优化，增加了引射短舱的进气流量，改善了尾喷口流场均匀度，明显提高了引射短舱性能。发展了空气桥技术，采用有限元方法进行了优化设计，对空气桥和天平进行一体化设计，并进一步发展了空气桥影响修正技术，解决了供气管路对天平测力的影响问题。发展了高精度流量测量控制技术，采用了数字阀、流量控制单元、短舱内部测量耙等技术，提高了流量的控制测量精度及测量不确定度，流量控制精度达到了0.1%，流量测量不确定度达到了0.3%，引射短舱落压比控制精度优于0.01。研制了短舱移动支撑装置，能够实现引射短舱的独立支撑，并实现短舱前后和上下位置的变化，用于开展短舱位置优化研究。最后，介绍了引射短舱的地面性能测试及风洞试验应用，给出了性能测试与数值模拟的对比结果和典型的风洞试验结果，试验结果表明动力影响使得飞机0°迎角升力减小，升力线斜率增大，失速迎角推迟。

Development in ejector nacelle simulation testing in low speed wind tunnel

The ejector nacelle has the capability to simulate the effect of jet flow and partly to simulate the effect of inlet flow, so it can be used to study the aerodynamic interference characteristic of engine on wing and high lift systems.Because of the advantages of short testing period and low cost,the ejector nacelle becomes a key testing technique for aircraft-engine integration research in wind tunnel .This paper presents the recent development in ejector nacelle simulation testing in low speed wind tunnel in China Aerodynamics Research and Development Center (CARDC).The flow field and characteristics of the ejector nacelle are simulated by computational fluid dynamics software.Based on numerical simulation results,the diameter of sonic nozzles and the position of sonic nozzles are optimized,the inlet mass flow is increased,the uniformity of outlet flow field and the performance of the nacelle are improved.The air bridge technique is developed and optimized by finite element analysis.The rigidity of the air bridge and the balance are matched basing on air bridge and balance assembly numerical simulation.The rigidity effect,the pressure effect,the temperature effect and the mass flow effect of the air bridge are corrected by serial tests.This correction further minimizes residual force of the air bridge.The high accuracy flow measurement and control techniques including the digital valves, the mass control units and the measurement rake are adopted in the ejector nacelle simulation testing.These techniques improve the precision of the control and the uncertainly of the flow measurement.The precision of the mass flow control is within 0.1%,the uncertainty of the mass flow measurement is 0.3% and the precision of pressure ration 0.01.The moving support system is developed for engine position optimization research.The performance test and wind tunnel test using the ejector nacelle are introduced.The test results show that the effect of the engine increases the slope of lift curve,increases the stall angle of attack,decreases the zero angle lift coefficient.